Naphthyl-n-cyanoformyl carbamates

ABSTRACT

Compounds of the formula: WHEREIN R is alkyl of 1 to 4 carbon atoms, X and Y are halogen of atomic number 9 to 35, nitro, alkyl of 1 to 4 carbon atoms or alkoxy of 1 to 4 carbon atoms, n is 0 to 3, and m is 0 to 3. The compounds are insecticides.

United States Patent Singer 51 Dec. 5, 1972 [54] NAPHTHYL-N-CYANOFORMYLCARBAMATES [72] Inventor: Malcolm Scott Singer, Riohmond,

- Calif. [73] Assignee: Chevron Research Company, San

Francisco, Calif.

[22] Filed: Sept. 8, 1970 [Zl] App]. No.: 70,498

[52] US. Cl. ..260/479 C, 260/544 Y, 424/300 [51] Int. Cl .l ..C07c125/06 [58] Field of Search ..260/479 C I Flory et al. ..260/479 PrimaryExaminer-James A. Patten Attorney-A. L. Snow, F. E. Johnston, G. F.Magdeburger, John Stoner, Jr. and Dix A. Newell [57] ABSTRACT Compoundsof the formula:

E i 0- -N CN R X"- Ym I I wherein R is alkyl of l to 4 carbon atoms, Xand Y are 3 Claims, N0 Drawings NAPHTHYL-N-CYANOFORMYL CARBAMABACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention is directed to aor B-naphthyl- N-cyanoformyl-N-alkylcarbamates and their use as insecticides.

2. Prior Art Netherlands U.S. Pat. No. 6,500,321 (64 Chem.Abs. 96335[1966]) discloses certain cyanothioformylphenyl carbamates as usefulinsecticides, fungicides, bactercides, herbicides, etc.

SUMMARY OF THE INVENTION It has now been discovered that aorB-naphthyl-N- cyanoforrnyl-N-alkyl carbamates are exceptionallyeffective in the control of insects, e.g., aphids, cockroaches, milkweedbugs and dock beetles.

A DESCRIPTION OF THE INVENTION Compounds of the present invention are ofthe formula:

X Ym

wherein R is alkyl of one to four carbon atoms, X and Y are halogen ofatomic number 9 to 35 (fluorine, chlorine or bromine), nitro, alkylindividually of one to four carbon atoms or alkoxy individually of oneto four carbon atoms, n is to 3, and m is 0 to 3.

R can represent, e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl or t-butyl. It is preferred that R is methyl.

X and Y (which may be the same or different) are preferably halogen ofatomic number 17 to 35 (chlorine or bromine), nitro groups, methyl ormethoxy. Preferably n and m will be from 0 to 1. The preferred compoundsof the present invention will have n and m equal to 0, i.e., theunsubstituted naphthyl carbamates.

Representative compounds of the present invention includel-naphthyl-N-cyanoformyl-N-methyl carbamate,2-naphthyl-N-cyanoformyl-N-methyl carbamate,1-(2-chloronaphthyl)-N-cyanoformyl-N-methyl carbamate,1-(4-chloronaphthyl)-N-cyanoformyl N-methyl carbamate,1-(2,4-chloronaphthyl)-N-cyanoformyl-N- methyl carbamate,l-(6-nitronaphthyl)-N-cyanoformyl-N-methyl carbamate,l-(3-methylnaphthyl)-N- cyanoformyl-N-methyl carbamate,2-(4-methoxynapthyl)-N-cyanoformyl-N-methyl carbamate and 1-naphthyl-N-cyanoformyl-N-ethyl carbamate.

The compounds of the present invention are prepared by first reacting anN-alkyl cyanoformamide with phosgene (present in a solvent such asbenzene) in the presence of an acid acceptor, at a temperature of fromto 35 C. for a time from 1 to 4 hrs, according to the followingequation:

wherein R is as described above and B is an acid acceptor. Generally,the N-alkyl cyanoformamide-phosgene mole ratio will be from 1:1 to 1:2.The amount of acid acceptor such as triethylamine, pyridine ordimethylaniline should be at least equal in mols to the amount of theN-alkyl cyanoformamide. The N-alkyl- N-chlorocarbonyl cyanoformamideproduct is then reacted with aor B-naphthol suitably substituted asdesired, per the following equation:

wherein R, X, Y, m and n are as described above, and B is an acidacceptor. The reactants in the latter reaction will preferably be inequirnolar amounts. An acid acceptor such as pyridine or dimethylanilineshould be present. The latter is preferred. The reaction is carried outin a solvent, e.g., benzene, in amount to 2 molar. Generally, the amountof acid acceptor will equal the mols of the N-alkyl-N-chlorocarbonylcyanoformamide. The latter reaction usually will be at a temperature of5 to 20 C. for a time of k to 4 hrs. The desired naphthyl-N-alkylcarbamate product can then be separated by stripping off the solvent andpurified by washing in ethanol, etc.

For example, a-naphthyl-N-cyanoforrnyl-N-methyl carbamate was preparedby reacting 8.4 g. (0.1 mol) of N-methyl cyanoforrnarnide with g. of a12.5 percent solution of phosgene in benzene and in the presence of 10.1g. (0.1 mol) of triethylamine. The N-methyl cyanoformamide andphosgene-benzene mixture was first mixed together and the triethylarnineadded slowly with cooling. The reaction mixture was allowed to warm upto room temperature with stirring continued for about one-half hour. Thetriethylamine hydrochloride was filtered out and the benzene solventevaporated leaving 8.1 g. of N-methyl-N-chlorocarbonyl cyanoformamide.This latter material and anaphthol were then dissolved in benzene.Dimethylaniline was added slowly with cooling. The mixture was allowedto warm up to room temperature. After one-half hour 15 ml. of water wasadded. A precipitate formed which was filtered out. The layers of thefiltrate were then separated, the benzene layer being washed with dilutehydrochloric acid and with water and dried with calcium chloride. Thesolvent was evaporated off leaving a solid material having a meltingpoint of l62-165 C. The nitrogen analysis showed 1 1.12 percent foundversus 1 1.0 percent calculated.

In addition to the specific formulations and application techniquesdescribed below, one or more of the carbamates of the present inventionmay be applied in other liquid or solid formulation to the insects,their environment, or hosts susceptible to insect attack. For example,they may be sprayed or otherwise applied directly to plants or soil soas to effect control of insects coming into contact therewith.

Fonnulations of the compounds of this invention will comprise a toxicamount of one or more carbamates and a biologically inert carrier.Usually they will also contain a wetting agent. Solid carriers such asclay, talc, sawdust and the like may be used in such formulations.Liquid diluents which may be used with these compounds include water andaromatic solvents. in addition these formulations may contain othercompatible pesticides, fillers, stabilizers, attractants and the like.

The concentration of the active ingredient to be used with inertcarriers, either solid or liquid carriers, will be dependent upon manyfactors, such as the particular carbamate compound which is used, thecarrier in or upon which it is incorporated, the method and conditionsof application, the insect species to be controlled, etc., the properconsideration of these factors being within the skill of those versed inthe art. In general, the toxic ingredients of this invention will beeffective in concentrations from about 0.0001 percent by weight to ashigh as 50 percent by weight or higher. Economically, of course, it isdesirable to use lower concentrations of this active ingredient. Thus,it is usually desirable to use less than percent by weight of the activeingredient in a particular composition.

The terms insecticide and insect as used herein refer to their broad andcommonly understood usage rather than to those creatures which in thestrict biological sense are classified as insects. Thus, the term insectis used not only to include small invertebrate animals belonging to theclass Insecta but also to other related classes of arthropods whosemembers are segmented invertebrateshaving more or fewer than six legs,such as spiders, mites, ticks, centipedes, worms and the like.

As examples of the usefulness of the compounds of the present invention,the following tests were conducted. For comparison phenylN-cyanoformyl-N- methyl carbamate, prepared generally by the proceduredescribed above, was also tested. Test results are reported in Table 1.

Test Procedures Aphids (Aphis gossypii Glover): An acetone solution ofthe candidate toxicant containing a small amount of nonionic emulsifierwas diluted with water to ppm. Cucumber leaves infested with the cottonaphids were dipped in the toxicant solution. Mortality readings werethen taken after 24 hours.

American Cockroach (Periplaneta americana L.): A 500 ppm acetonesolution of the candidate toxicant was placed in a microsprayer(atomizer). A random mixture of anesthetized male and female roaches wasplaced in a container and 55 mg. of the abovedescribed acetone solutionwas sprayed on them. A lid was placed on the container. A mortalityreading was made after 24 hours.

Milkweed Bug (Oncopeltus fasciatus): A 250 ppm acetone solution of thecandidate toxicant was placed in a microsprayer (atomizer). A randommixture of anesthetized male and female milkweed bugs was placed in acontainer and 55 mg. of the abovedescribed acetone solution was sprayedon them. A lid was placed on the container. A mortality reading was madeafter 24 hours.

Dock Beetle (Gastrophysa cyanea Melsh): A 40 ppm toxic solution wasprepared by mixing 10 mg. toxicant to 10 ml. acetone and diluting withwater. Dock weed (Rumex) leaves were dipped and held immersed for about3 seconds in the toxicant solution. The leaves were then dried andplaced in contact with dock beetle larvae. The larvae and leaves wereheld in an incubator at 75 F. for 24 hours, after which mortalitydeterminations were made.

TABLE I Mortality Compound Aphids Cock- Milkweed Dock roach bug Beetlel-naphthyl-N- cyanoformyl-N- methyl carbamate 96 7 3 100 PhenylN-cyanoformyl- N-methyl carbamate 0 wherein R is alkyl of one to fourcarbon atoms, X and Y are halogens of atomic number 9 to 35 (chlorine,fluorine or bromine), nitro groups, alkyl groups individually of one tofour carbon atoms, alkoxy groups individually of one to four carbonatoms, and n is 0 to 3,andmis0to 3.

2. Compound of claim 1 wherein X and Y are halogen of atomic number 17to 35, nitro groups, methyl or methoxy, n is 0 to l, and m is O to 1.

3. Compound of claim 1 wherein R is methyl, and m and n are 0.

2. Compound of claim 1 wherein X and Y are halogen of atomic number 17to 35, nitro groups, methyl or methoxy, n is 0 to 1, and m is 0 to
 1. 3.Compound of claim 1 wherein R is methyl, and m and n are 0.